Mechanically actuated vibrating relay



p 1932 R. D. SALMON ET AL MECHANICALLY ACTUATED YIBRATING RELAY Filed March 5. 1950 mmnr - lNVENTC-R REGINALD o. SALMON HARRY CLIFFO ATTORNEY Patented Sept. 27, 1932 UNITED STATES PATENT OFFICE REGINALD DENNIS SALMON AND HARRY CLIFFORD, OF CROYDON, ENGLAND, AS- SIGNORS TO CREE!) AND COMPANY, LIMITED, OF CROYDON, ENGLAND MEGHANIGALLY ACTUATED YIBRATING REL AY Application filed March 3, 1930, Serial No. 432,828, and in Great Britain January 1, 1930.

This invention relates to relays and like devices as used in signalling apparatus.

More specifically stated, the invention relates to relays in which an electromagnet controls mechanical power for the operation of telegraphic or like signalling apparatus.

In telegraphic and like signalling apparatus it has already been found preferable in many cases to substitute mechanical methods of operation where possible, in lieu of purely electrical or electromagnetic methods. By this means, operations are performed by mechanical power under the control of electromagnetic means', instead of directly by power 3 magnets and the like.

The examples given in the present specification show the invention as applied to apparatus in which alternating and intermittent movements of a control member from one to the other of two positions cause corresponding movements by mechanical power of a second member. The first member may conveniently be the armature of an electromagnet responsive to telegraphic or like signalling currents. The second member which is actuated by mechanical power may be utilized to effect mechanical operations in signalling apparatus, or may be utilized to operate switch contacts for comparatively heavy currents. An arrangement of this description is generally referred to as a mechanical relay. The invention however, is not limited to the application to any particular form of such so called mechanical relays or in effect to mechanical relays whatsoever, as it is capable of application to many forms of apparatus mechanically actuated under electromagnetic control. In certain cases the elementconstituting the second member which is actuated by mechanical power does not necessarily perform alternating and intermittent movements similar to the controlling member and therefore the term mechanical relay would not be readily applicable to the arrangement. Alternative applications of the invention may comprise arrangements in which the alternating and intermittent movements of the controlling member cause corresponding intermittent movements of one or more cam sleeves. The

present examples are illustrative, but not limitative. The invention will be defined in the appended claims.

The invention embodies a principle which is already known as applied in a particular manner to electromagnetic relays. Such relays are known as vibrating or Gulstad relays. This principle is well-known and may be stated to consist of applying electromagnetic retroaction on the armature of a polarized electromagnetic relay, which retroaction is timed by the electrical constants of associated condensers, inductances and resistances. The armature of the relay is thus maintained in a state of constant oscillation or vibration from one side to the other and the rate of vibration is determined by the Values of these electrical constants. On telegraph circuits, if this rate is suitably adjusted to that of the basic speed of signalling'reversals of the distant transmitter, the strength of the line current received which is required to reproduce signals based on cyclic rev'ersalsof this character need only be that suificient to suppress the locally induced oscillation of the armature. The power required to move the armature from one position to the other is suppliedby a local source of electrical energy. The line current need only be of sufficient strength to prevent the initiation of this movement.

The present invention provides means whereby retroaction on the armature of a polarized relay in telegraphic and like signalling apparatus is controlled by mechanical means. This is in turn controlled by the movement of the said armature, as in the case of a vibrating or Gulstad relay. The invention in its broadest aspect consists essentially of an armature, a member actuated by mechanical power upon movement of said armature for efl'ecting the operation of telegraphic or like apparatus, local means controlled by said member tending to replace.

said armature, and electromagnetic windings adapted to hold said armature in opposition to said local means.

In one embodiment thereof retroaction is entirely mechanical, being mechanical in action and mechanically timed and controlled. The essential elements consist of an electromagnetic relay, an armature thereof operable between two positions, a distance piece actuated by mechanical power upon each movement of said armature in a direction contrary to said movement, two independent levers each in operative relation with one side of said armature and said distance piece, adjustable spring means acting on said levers and tending to cause said armature to follow the movement of said distance piece, and windings on said elec-- tromagnetic relay to hold said armature to one side or the other in accordance with the direction of current therein in opposition to said'spring means.

In another embodiment retroaction is electro-magnetic but timed and controlled by mechanically actuated means consequent upon movement of the armature, and consists of an electro-magnetic relay, an armature therefor operable between two positions, switch contacts actuated by mechanical power from one position to another upon each movement of said armature windings on said electromagnetic relay in circuit with a local source of electrical energy and said switch contacts causing a local tendency to actuate said armature in a direction contrary to each said movement, and other windings on said electromagnetic relay to hold the armature to one side or the'other in accordance with the direction of current therein in opposition to said local tendency.

A very useful feature in the invention consists of means whereby in any of the embodiments described a single adjustment suflices to regulate equally and simultaneously the local retroactive tendency for both directions of movement of the controlling relay armature. Further features will be evident from the following description and accompanying drawing in which Fig. 1 shows diagrammatically a mechanical relay with mechanical retro-action, whilst Fig. 2 shows a similar mechanical relay with electromagnetic retroaction, but mechanically timed and controlled.

Referring to'Fig. 1 an armature 1 of a telegraphic or like polarized relay 2 actuates through connecting rod 3 the escapement 4 of a friction clutch the driving member (not shown) of which is rotated at a constant speed by any convenient source of mechanical power (not shown). The driven member 5 rotates a half revolution at each actuation of the relay armature lfrom one side to the other and carries an eccentric pin 6 which actuates a rock shaft 7, through arm 8 fixed thereto and connecting rod 9. A second arm 10 fixed to rockshaft 7 may be utilized to perform various functions in the operation of telegraphic apparatus or may be utilized as shown to make contact alternately with one or the other of two contact screws (11 and 12) by spring contact tongue 13. The arrangement described thus forms a mechanical relay in which arms fixed to the rock shaft 7 are actuated by mechanical power from one position to another in accordance with the movements of the armature 1.

Pivoted to a third arm 14 fixed to the rock shaft 7 is another connecting rod 15, which actuates a distance piece 16 alternately between and against two independent levers 17 and 18 pivoted on common pivot pin 19. The levers 17 and 18 are extended beyond the distance piece 16 to engage either side of the armature 1. The opposite ends of the levers are extended beyond the pivot 19 and are connected by pivoted links 20 and 21 to one end of a common spring 22, the tension of which is adjustable by means of lever 23 connected to the other end, and adjusting screw 24. The arrangement of links 20 and 21, spring 22 and lever 28 forms a ready means of adjusting the spring pressure of arms 17 and 18 and in a manner which ensures that this spring pressure is substantially equal for both arms.

When the armature 1 of the relay moves over from one position to the other, say from left to right, escapement 4 releases the tooth of the driven member 5 which is thereupon rotated by mechanical power and is arrested a half revolution later on the opposite tooth of the escapement 4. The eccentric pin 6 in the driven member 5 moves to the opposite position and rotates rock shaft 7 through a small angle, in this case in a contra clockwise direction, by means of arm 8 and connecting rod 9. Distance piece 16 is thus actuated, in this case from the right hand position to the left hand through the medium of arm 14 and connecting rod 15. In moving to its extreme left hand position distance piece 16 presses the lever 17 away from armature 1 and leaves lever 18 pressing under tension of spring 22 against the opposite side of the armature. When no current is flowing in the relay coils the attraction due to the magnetism of the polarizing magnet will hold the relay armature in this position. If the tension of spring 22 is now adjusted by screw 2% so that the pressure of lever 18 on the extremity of armature 1 is just sufficient to overcome this magnetic attraction, the armature 1 will be mechanically actuated to the left hand side where the armature will again beheld by the attraction of the polarizing magnet if the relay is in a neutral condition. The actuation of relay armature 1 to this position moves escapement 4 and releases the driven member 5 for a. further half revolution. The eccentric pin of the mechanical relay rotates the rock shaft 7 through a small angle in a clockwise direction and this causes the return of distance piece 16 from the left hand position to the right. Lever 17 is now permitted to press against armature 1 under tension of spring 22, whilst lever 18 is moved away from the opposite side. This actuates armature 1 to the left again and actuates the mechanical relay a further half revolution. This action is continuous and if the driving member of the clutch of the mechanical relay is rotated at a constantspeed, the controlling armature 1 of the electromagnetic relay and the actuated member 10 on rock shaft 7 will be maintained in oscillation at a frequency which is determined by the speed of the driving member of the. mechanicalrelay. It will be noticed that this mechanical retroaction does not immediately oppose and reverse the movement of armature 1 which has caused it. This is effected during the half revolution of the clutch escapement which follows the movement of armature 1. Armature 1 is therefore sprung firmly from one position to the other at each actuation. By the nature of the construction of the mechanical relay the actuated member 8 is also firmly and decisively carried from one position to the other at each release of the driving member (not shown) by escapement 1. The oscillations are therefore completely formed.

If the oscillations are now timed by adj usting the speed of rotation of the clutch driving member to correspond with the speed of signalling reversals of a telegraph circuit, the current in the coils of the relay 2 will only be required to maintain the armature 1 to one side or the other in accordance with the polarity of signal elements against the tension of spring 22. This, as already stated, is read ily adjustable by screw 24, for both levers 17 and 18 simultaneously. Upon the line current changing from one polarity to the other in the formation of a signal element, as soon as the current diminishes to a Value which is no longer sufficient to hold the armature against the pressure of lever 17 or 18 due to spring 22, the armature 1 is sprung over to the opposite side. It is this anticipating feature which renders the arrangement so useful in the same way as the corresponding effect in vibrating relays with electromagnetic retroaction.

In the alternative arrangement shown in l i g. 2, additional windings 25 and 26 are provided on the relay and are connected as shown to two contact screws 27 and 28. Contact tongue 29 actuated by the rock shaft 7 of the mechanical relay oscillates between these two contact screws and is connected to one pole of a local battery 80. The other pole of the battery is connected through an adjustable resistance 31 to the junction of the additional windings 25 and 26. This arrangement provides electromagnetic retroaction which is controlled by the movements of the mechanical actuated member of the mechanical relay, i. e. rock shaft 7. In this case when the controlling electromagnetic relay is at rest contact tongue 29 is making contact with one or the other of contact screws 27 and28 and the current thereby flowing in the respective winding 25 or 26 is in a direction which tends to actuate the armature 1 over to the opposite side. The strength of this current may be adjusted by resistance 31 so that the effect due to the current in the line or main winding of the relayis just sufficient to hold the armature against'its contact stop in opposition to this local accelerating force. When the line current diminishes in strength preparatory to changing in direction the armature is actuated over to the opposite position. The mechanical relay in the subsequent half revolution of the friction clutch moves contact tongue (29) over to the opposite contact screw and reverses the direction of the localaccelerating force. It will be seen that if there is no holding current in the main winding of the N relay the armature and consequently the rock shaft 7 of the mechanical relay will be maintained in a state of'constant oscillation in the same way as in the previous example.

The arrangements described in the preceding examples may be variously modified to suit the apparatus in which it is desired to incorporate the invention. It will be appreciated that these examples are only illustrative of the manner in which the invention may be carried out. 7

- What is claimed is:

1. In signalling apparatus a relay comprising an armature operable between two positions, a member likewise operable for effect- M tion of current therein in oppositionto said local means.

2. In signalling apparatus a relay comprise ing a magnet an armature therefor operable between two positions, a distance piece actuated by mechanical power upon each movement of said armature in a direction contrary 1 to said movement two independent levers each in operative relation w1th one side of said armature and said distance piece, spring means acting on said levers tending to cause said armature to follow the movement of said distance piece, and windings associated with said magnet adapted to hold the said armature to one side or the other in accordance with the direction of current in said windings in opposition to said spring means.

3. In signalling apparatus a relay comprising a magnet, an armature therefor operable between two positions, switch contacts actuated by mechanical power from one position to another upon each movement of said armature, windings associated with said magnet in circuit with a local source of electrical energy and said switch contacts causing a local tendency to actuate said armature in a direction contrary to each said movement, and other windings associated with said magnet adapted to hold said armature to one side or the other in accordance with the direction of current in said other windings in opposition to said local tendency.

4. In signalling apparatus a relay comprising a magnet, an armature therefor operable between two positions, a contact tongue actuated'by mechanical power from one contact stop to another upon each movement of said armature, two windings associated with said magnet the junction of which two windings is connected through an adjustable resistance and local source of electrical energy to said contact tongue and of which the two extremities of said windings are connected to the two said contact stops respectively, and a third winding associated with said magnet adapted to hold said armature to one side or'the other in accordance with the direction of current in said third winding in opposition to a current in either of said two windings.

5. In signalling apparatus a relay comprising a magnet, an armature therefor operable between two positions, a distance piece actuated by mechanical power upon each movement of said armature in a direction contrary to said movement, two independent levers between which said armature and said distance piece are adapted to operate, a spring connected by individual links at one end to an extension on each of said levers, screw adjusting means connected to the other end of said spring, and windings associated with said magnet adapted to hold said armature to one side or the other in accordance with the direction of current in said windings in oppsition to said spring.

6. In signalling apparatus a relay comprising a magnet, an armature therefor, an escapement actuated by said armature to release the driven member of a power transmission clutch for half a revolution only at each movement of said armature, an eccentric on the driven member of said clutch actuating a rockshaft alternately at each half revolution through a small angle, retroactive means controlled by said rockshaft causing a tendency to actuate said armature in a direction contrary to each initiating movement of said armature, and windings associated with said magnet adapted to hold said armature to one side or the other in accordance with the direction of current in said windings in opposition to said retroactive means.

, 7 The combination of an electromagnetic relay having an armature operable between two positions, two levers pivotally mounted with said armature located therebetween,and

means actuated in response to the movement of said armature to either position to cause the corresponding lever to restore said armature to the position from which it was last moved, each of said levers having an effective restoring force less than the holding force of said relay when energized.

8. The combination of an electromagnetic relay having an armature operable between two positions, two elements, one for moving the armature in one direction and the other for moving it in the opposite direction, and means actuated in response to the movement of the armature to either position to render the corresponding element effective to restore the armature to the position from which it was last moved, each of said elements having an effective restoring force less than the holding force of said relay when energized.

9. In signalling apparatus, the combination of a driven shaft, an escapement for said shaft, means responsive to rotation of said shaft after each operation of said escapement for releasing said escapement, whereby said escapement normally operates continuously, and a polar relay having an armature connected to said escapement for restraining the operation of said escapement when said relay is energized in either position.

In witness whereof we hereunto subscribe our names this eighth day of February 1930.

REGINALD DENNIS SALMON. HARRY CLIFFORD. 

